The present invention relates generally to pneumatic valves.
Pneumatic or vacuum valves usually include a housing member defining an inlet passage and outlet passage. A diaphragm is typically supported by the housing member and is movable relative to a seating surface formed on an extension of one of these passages such as the outlet passage. The diaphragm, in cooperation with the housing defines a pressure chamber having a control port for communicating pressure to the pressure chamber. In operation the diaphragm is moved in and out of engagement with the seating surface (sealing area) to control communication between the inlet passage to the outlet passage under the influence of control pressure signals. Typically these diaphragms are fabricated from a resilient, rubber-like product. Quite often the seating surface contains surface irregularities which prevent the formation of an adequate seal upon engagement by the diaphragm. This is especially true if housing is injection molded.
It is an object of the present invention to provide a valve which is devoid of deficiencies found in the art.
It is another object of the present invention to provide an improved diaphragm which self-compensates for surface irregularities formed in a valve sealing area or seating surface.
Accordingly the invention comprises: a valve including a plurality of passages, an annular sealing area formed relative to one of the passages, and a diaphragm supported relative to the sealing area and movable in response to a force differential applied thereacross including a thin, planar, flexible, non-metallic membrane for sealably engaging with the sealing area.
Many other objects and purposes of the invention will be clear from the following detailed description of the drawings.